Other Assets - Additional Information (Detail) (Monroe Properties [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Monroe Properties [Member]
Other Assets [Line Items]
Lease inducements to tenants	$ 5

This item represents the deferred charge for an incentive or inducement granted by a lessor to a lessee, in order to motivate the lessee to enter the lease agreement, which incentive or inducement is to be recognized as a reduction of rental revenue over the lease term.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 25

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e40010-112707

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 25

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e40019-112707

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Lease Incentive

-URI http://asc.fasb.org/extlink&oid=6516590

Name:	us-gaap_IncentiveToLessee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant